The use of thin walled plastic shells for products have included a cast shell of thermoplastic material with a decorative feature formed therein. One example is set forth in U.S. Pat. No. 4,610,620, which discloses apparatus for molding plural colored plastic hollow shells by a process in which a decorative pinstripe is formed as an integrally bonded joint between first and second segments of the shell. The joint between the shell components is used to replace a mechanical connection therebetween and to provide a pinstripe decorative feature in the shell component. However, the decorative pinstripe is formed only along the joint line of the joined parts and is not formed in situ in a base layer.
U.S. Pat. No. 4,562,025 discloses a mold method and apparatus for forming multicolored plastic shells which have first and second colored segments on the cast shell portions of the finished product. However, there are no decorative features formed in situ on the cast shell components of the trim part.
U.S. Pat. No. 4,562,032 discloses a method for forming grain coverings on reaction injection molded articles. Such grained shells are formed, in some cases, to have an integrally formed stitching feature around the perimeter thereof to provide an appearance of stitched materials.
While the above patents disclose shells cast from thermoplastic material which include decorative color and trim features, they do not disclose a method for providing decorative features such as colored lettering or colored stitching in situ on an eye discernible surface of a finished article formed by the method of depositing thermoplastic material on a heated mold surface.
Various other proposals have been suggested for providing decorative features on plastic products, however, the problem with prior approaches has been that they require separate connectors or adhesives to provide the decorative features on the outer surface of the product.